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Sexually transmitted disease thresholds in Manitoba, Canada
Ann M Jolly1, Michael E K Moffatt, Margaret V Fast
1University of Manitoba, Winnipeg, Manitoba. ann_jolly@hc-sc.gc.ca
Annals of Epidemiology
|September 20, 2005
Summary
A small group of individuals with repeated sexually transmitted infections (STIs) and their partners drive STI persistence. Understanding sexual network structure is key to managing STI epidemics.
Area of Science:
- Public Health
- Epidemiology
- Infectious Disease Control
Background:
- Sexually transmitted infections (STIs) persist in populations due to a small, core group of infected individuals and their partners.
- The reproductive number (R0) quantifies transmission potential within groups, indicating epidemic thresholds.
Purpose of the Study:
- To identify the core group responsible for STI persistence.
- To test the hypothesis that individuals with repeated bacterial STIs and their partners form the core group.
- To differentiate core individuals from singly infected non-core individuals.
Main Methods:
- Data from 1990-1992 in Manitoba, Canada, were extracted from notifiable disease and health insurance registries.
- Individuals with repeated gonorrhea, chlamydia, and coinfections were compared using logistic regression.
- Reproductive numbers were calculated using sex partner data.
Main Results:
- Coinfected individuals were youngest, of aboriginal descent, and had the lowest incomes.
- Repeaters were older, had higher incomes, and fewer aboriginal individuals.
- Reproductive numbers varied: 1.09 for coinfected, 1.01 for repeaters, and 2.41 for chlamydia repeaters.
Conclusions:
- Different groups contribute unequally to STI endemicity.
- Sexual network structure significantly influences epidemic thresholds.
- Targeted interventions within core groups may be effective for STI control.
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